This article in the Lancaster Telegraph suggests the practice may have ended in 2007, but between 2000 and then the Burnley Council used the Regulation of Investigatory Powers Act (RIPA) of 2000 to spy on its own staff.

The regulation was brought in in 2000 and allowed council bosses to carry out surveillance on residents they suspected of committing crimes.

The vast majority of uses of the act relate to offences such as benefit fraud, fly-tipping and anti-social behaviour.

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A Burnley Council spokesman said: “The vast majority of cases where we have used RIPA authorisations were to tackle noise nuisance, anti-social behaviour, fly-tipping and benefit fraud – all things we know our residents want us to sort out.